1. Field of the Invention
The present invention relates to a digital image processor such as a digital printer and a data processing thereof.
2. Description of the Prior Art
In a digital printer or the like, digital image data are read by an image reader section, modified by an image processor section according to the print characteristics and edited according to the editing mode specified with an operational panel. After the data processing, the image is printed on a paper by a printer section.
In the image reader section, a digital image of a document is read at a specified resolution. Therefore, the information on the document which exceeds the resolution is lost inevitably when the image is read. In the printer section, the image data can not reproduced with perfect fidelity. Therefore, an image printed on the paper is reproduced by the printer, the information is lost inevitably to a certain degree and the quality of the image regenerated by the printer is degraded.
The degradation of image may not be a large problem when the image is reproduced from the original document. However, when the image is reproduced again from the hard copy, the quality of the image may be degraded to a large degree. Some printers use an outline font. However, even if an image is reproduced with fidelity with use of outline font, the quality of the hard copy of the reproduced image is degraded, especially as to the contour.
There is no problem if the copying is performed from the digital source in a floppy disk or the like. However, a hard copy (analog image) is reproduced again in many cases as to the compatibility or the convenience. Therefore, it is desired to improve the quality of hard copy.
In U.S. Pat. No. 4,847,641, a contour line of image is improved by estimating the original pattern or by using smoothing. However, this method cannot restore the deformed contours which occurred on reading and on printing.